<template>
  <div class="app-container">
    <!--表单-->
    <el-form :inline="true" class="demo-form-inline">
      <el-form-item>
        <el-date-picker
          v-model="startDate"
          type="date"
          placeholder="选择开始日期"
          value-format="yyyy-MM-dd" />
      </el-form-item>
      <el-form-item>
        <el-date-picker
          v-model="endDate"
          type="date"
          placeholder="选择截止日期"
          value-format="yyyy-MM-dd" />
      </el-form-item>
      <el-button
        :disabled="btnDisabled"
        type="primary"
        icon="el-icon-search"
        @click="showChart()">查询</el-button>
    </el-form>
    <div id="chart" class="chart" style="height:500px;" />
  </div>
</template>
<script>
    import echarts from 'echarts'
    import api from '@/api/vod/videoVisitor'

    export default {
        data() {
            return {
                courseId: '',
                startDate: '',
                endDate: '',
                btnDisabled: false
            }
        },
        created() {
            this.courseId = this.$route.params.id
            // 初始化最近十天数据
            let currentDate = new Date();
            this.startDate = this.dateFormat(new Date(currentDate.getTime()-7*24*3600*1000))
            this.endDate = this.dateFormat(currentDate)
            this.showChart()
        },
        methods: {
            showChart() {
                api.findCount(this.courseId, this.startDate, this.endDate).then(response => {
                    this.setChartData(response.data)
                })
            },
            setChartData(data) {
                // 基于准备好的dom，初始化echarts实例
                var myChart = echarts.init(document.getElementById('chart'))
                // 指定图表的配置项和数据
                var option = {
                    title: {
                        text: '观看课程人数统计'
                    },
                    xAxis: {
                        data: data.xData
                    },
                    yAxis: {
                        minInterval: 1
                    },
                    series: [{
                        type: 'line',
                        data: data.yData
                    }]
                }
                // 使用刚指定的配置项和数据显示图表。
                myChart.setOption(option)
            },
            dateFormat(date) {
                let fmt = 'YYYY-mm-dd'
                let ret;
                const opt = {
                    "Y+": date.getFullYear().toString(),        // 年
                    "m+": (date.getMonth() + 1).toString(),     // 月
                    "d+": date.getDate().toString(),            // 日
                    "H+": date.getHours().toString(),           // 时
                    "M+": date.getMinutes().toString(),         // 分
                    "S+": date.getSeconds().toString()          // 秒
                    // 有其他格式化字符需求可以继续添加，必须转化成字符串
                };
                for (let k in opt) {
                    ret = new RegExp("(" + k + ")").exec(fmt);
                    if (ret) {
                        fmt = fmt.replace(ret[1], (ret[1].length == 1) ? (opt[k]) : (opt[k].padStart(ret[1].length, "0")))
                    };
                };
                return fmt;
            }
        }
    }
</script>

<style scoped>

</style>
